Cross compiling simple pcap example

[Kai Ruottu]

20.6.2011 15:19, Kent Kvarfordt kirjoitti:
> List,
>
> I am trying to cross compile a simple pcap example (see below) on a
> 64-bit Ubuntu 11.4 installation targeting a 32-bit Ubuntu 11.4
> installation.  When I set the -m32 option, the example compiles fine,
> but fails to link with the following error.
>
> /usr/bin/ld skipping incompatible /usr/lib/libpcap.so when searching for -lpcap
>
> This makes sense given the /usr/lib/libpcap.so is the 64-bit pcap
> library.  I tried installing the 32-bit pcap package along side the
> 64-bit package, but the installation failed saying the
> packages/libraries could not co-exist.

This seems to be a bug in the Ubuntu 11.04 install schemes. When
investigating the 32-bit library install place, one sees :

[root@localhost host-Ubuntu11.04_i686]# ar xv 
/home/Asennus/Ubuntu/11.04/i386/libpcap0.8_1.1.1-2_i386.deb data.tar.gz
x - data.tar.gz
[root@localhost host-Ubuntu11.04_i686]# tar tvzf data.tar.gz
drwxr-xr-x root/root         0 2010-05-09 18:44:28 ./
drwxr-xr-x root/root         0 2010-05-09 18:44:26 ./usr/
drwxr-xr-x root/root         0 2010-05-09 18:44:33 ./usr/lib/
-rw-r--r-- root/root    206936 2010-05-09 18:44:33 
./usr/lib/libpcap.so.1.1.1
<snip>
lrwxrwxrwx root/root         0 2010-05-09 18:44:31 
./usr/lib/libpcap.so.0.8 -> libpcap.so.1.1.1

So the place is just the same :(  BUT even the 32-bit Ubuntu 11.04
doesn't put the 32-bit libraries into '/usr/lib' but into
'/usr/lib/i386-linux-gnu'. So the basic question is where the 32-
bit libraries should be in the 64-bit system? The rest is easy as
a pie: just unpack the '.deb' archive somewhere, then untar the
'data.tar.gz' in it and copy/move the required stuff where it should
be.

Of course this kind of 'manual install' will not be known by the
package managers but who will care...